ABSTRACT
The generation of light from the oxidation of oxalic esters with hydrogen peroxide has been applied to the detection of luminescent materials. In order to improve the efficiency of this method, which is less than 0.1%, and to enhance the selectivity for target analytes, an in-depth investigation of the oxalate ester-hydrogen peroxide reaction has been conducted. A kinetic model has been developed based on the effects of catalysts, reagents and reaction conditions for maximum light production. Application of the model to liquid chromatography through the "time-dependent emission window" concept affords a predictable maximum sensitivity for selected analytes. Application to the detection and quantitation of met- and leu-enkephalins which have been labelled with naphthalene-2,3-dicarboxyaldehyde/cyanide provides support for this methodology. Other bioanalytical applications are presented.
Subject(s)
Luminescent Measurements , Pharmaceutical Preparations/analysis , Humans , Indicators and ReagentsABSTRACT
A method is described to evaluate the permeation characteristics of glove materials by chemical solvents. The collecting medium (helium) is continuously monitored by a flame ionization detector (FID) of a gas chromatograph (GC). Immediately following a steady-state condition, quantitative data are acquired on-line by a computer. A two-position GC sampling valve and computer-controlled data acquisition and analysis require minimal operator attention. For the 8 materials and 6 solvents investigated, thickness-normalized breakthrough times and steady-state permeation rates ranged from 9.10 min/mil to greater than 4 hr/mil and from 0.2048 to 9112 micrograms/min/cm2/mil, respectively. A modification of the procedure which allowed the determination of the effect of temperature on permeation for 4 glove/solvent pairs was evaluated also.
